Image sensor, output method, phase focusing method, imaging device, and terminal

ABSTRACT

The present disclosure discloses a pixel information output method of an image sensor. The image sensor includes a photosensitive unit array including a plurality of photosensitive units, a filter cell array including a plurality of filter cells, and a micro-lens array including a plurality of micro-lenses. The filter cell array is located between the photosensitive unit array and the micro-lens array. Each micro-lens covers a filter cell and a photosensitive unit. Each photosensitive unit includes a plurality of photosensitive pixels. The method includes: determining an output mode according to a mode selection instruction; controlling exposure of the photosensitive unit array and reading outputs of the photosensitive unit array, pixel information of the plurality of photosensitive pixels of a same photosensitive unit being combined to be output when selecting a first output mode. The present disclosure also discloses a phase focusing method, an image sensor, an imaging device, and a terminal.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.15/632,697, filed Jun. 26, 2017, which is a continuation ofInternational Application No. PCT/CN2016/101704, filed Oct. 10, 2016,which claims priority to Chinese Patent Application No. 201510963242.5,filed Dec. 18, 2015. The entire disclosures of the aforementionedapplications are incorporated herein by reference.

FIELD

The present disclosure relates to image device technologies, andparticularly, to a pixel information output method of an image sensor, aphase focusing method, an image sensor, an imaging device, and aterminal.

BACKGROUND

Currently, a pixel structure, in a sensor of a phone camera, includes amicro-lens corresponding to a pixel unit and has two problems. First,the size of the pixel unit of the sensor of the phone camera becomessmaller and smaller, and the imaging sensitivity and the SNR (signalnoise ratio) of the sensor need to be improved, this is not benefit forimage quality of pictures. Second, the micro-lens receives light in alldirections for imaging of the same pixel unit. The pixel unit does notdistinguish directions of the received light, so the pixel unit cannotmeet a condition of the phase detection and cannot provide a basis forphase focusing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of an image sensor, according to anembodiment of the present disclosure;

FIG. 2 is a schematic diagram of a filter cell array using a Bayerarray, according to an embodiment of the present disclosure;

FIG. 3 is a schematic diagram of a filter cell array using a Bayerarray, according to an embodiment of the present disclosure;

FIG. 4 is a flow chart of a pixel information output method of an imagesensor, according to an embodiment of the present disclosure;

FIG. 5 is a schematic diagram of imaging, according to an embodiment ofthe present disclosure;

FIG. 6 is a schematic diagram of imaging of the related art;

FIGS. 7 (1) and (2) are schematic diagrams, illustrating inputs of theimaging light in the related art;

FIG. 8 is a flow chart of a phase focusing method, according to anembodiment of the present disclosure;

FIG. 9 is a block diagram of an imaging device, according to anembodiment of the present disclosure;

FIG. 10 is a block diagram of a terminal, according to an embodiment ofthe present disclosure;

FIG. 11 is a flow chart of an imaging method, according to an embodimentof the present disclosure;

FIG. 12 is a flow chart of an imaging method, according to an embodimentof the present disclosure;

FIG. 13 is a flow chart of an imaging method, according to anotherembodiment of the present disclosure.

DETAILED DESCRIPTION

Embodiments of the present disclosure will be described in detail in thefollowing descriptions, examples of which are shown in the accompanyingdrawings, in which the same or similar elements and elements having sameor similar functions are denoted by like reference numerals throughoutthe descriptions. The embodiments described herein with reference to theaccompanying drawings are explanatory and illustrative, which are usedto generally understand the present disclosure. The embodiments shallnot be construed to limit the present disclosure.

In order to enhance the imaging sensitivity and the SNR of the phonecamera and achieve the phase detection, in embodiments of the presentdisclosure, a plurality of photosensitive pixels form a group sharingone micro-lens, pixel information of each photosensitive pixel of agroup of the photosensitive pixel is respectively read to distinguishimaging light. The plurality of photosensitive pixels can be combinedfor imaging to reach a higher imaging sensitivity and a higher SNR, andthe phase difference information detection function can be achievedthrough different entrance directions of the light.

FIG. 1 is a schematic diagram of an image sensor, according to anembodiment of the present disclosure. As shown in FIG. 1, the imagesensor 100 includes a photosensitive unit array 10, a filter cell array20, and a micro-lens array 30.

Wherein, the filter cell array 20 is located between the photosensitiveunit array 10 and the micro-lens array 30. The photosensitive unit array10 includes a plurality of photosensitive units 11. The filter cellarray 20 includes a plurality of filter cells 21. The micro-lens array30 includes a plurality of micro-lenses 31. Each micro-lens 31 covers acorresponding filter cell 21 and a corresponding photosensitive unit 11.Each photosensitive unit 11 includes a plurality of photosensitivepixels 110. For example, in one embodiment of the present disclosure,each photosensitive unit 11 includes 2*2 photosensitive pixels 110.

In some embodiments of the present disclosure, the filter cell array 20includes a Bayer array (Bayer pattern). Using a Bayer structure,traditional algorithms for the Bayer structure can be employed toprocess image signals so that there is no need to make a majoradjustment on hardware structures.

Referring to FIG. 2 and FIG. 3, in the Bayer structure, 2*2 filter cells21 form a filter structure 22. The 2*2 filter cells 21 are green, red,blue, and green filter cells 21.

In the structure of a conventional the filter cell array 20, each filtercell 21 corresponds to a photosensitive pixel 110 and an image pixel. Inthe embodiments of the present disclosure, the filter cell array 20employs the Bayer structure. The difference is that each filter cell 21corresponds to a plurality of photosensitive pixels 110, such as fourphotosensitive pixels 110, which means that the plurality ofphotosensitive pixels 110 correspond to one filter unit 21 having a samecolor.

In summary, in the image sensor 100 of the embodiments of the presentdisclosure, the plurality of photosensitive pixels 110 form a group andshare one micro-lens 31. In other words, instead of corresponding to onephotosensitive pixel, one micro-lens 31 of the image sensor 100corresponds to the plurality of photosensitive pixels 110. And the groupof the photosensitive pixels 110, that the photosensitive pixels 110 inthe photosensitive unit 11, corresponds to the filter cell 21 having thesame color.

Based on the structure of the image sensor 100 shown in FIG. 1, a pixelinformation output method of the image sensor 100 is explained below.FIG. 4 is a flow chart of a pixel information output method of an imagesensor 100, in accordance with one embodiment of the present disclosure.As shown in FIG. 4, the method includes the following steps to:

S1, determine an output mode according to a mode selection instruction.

In the embodiment of the present disclosure, the output mode includes afirst output mode and a second output mode. The first output mode can beunderstood as an output mode for improving the imaging sensitivity andthe SNR. The second output mode can be understood as an output mode forthe phase focusing and the depth information test.

S2, control exposure of the photosensitive unit array 10, and readoutputs of the photosensitive unit array 10. Wherein, pixel informationof the plurality of photosensitive pixels 110 of the same photosensitiveunit 11 is combined to be output when the first output mode is selected.

Specifically, when the pixel information of the plurality ofphotosensitive pixels 110 of the photosensitive unit 11 corresponding tothe same micro-len 31 is combined to be output, compared with the outputsignal of one photosensitive pixel corresponding to one micro-lens, thecombined output signal of the plurality of photosensitive pixels 110,such as N photosensitive pixels, is improved by N times. Since the noiseis proportional to the square root of the signal, that is, noise∝(Signal)^(1/2), the signal becomes N times than ever, the noise isN^(1/2) times than ever, and both the imaging sensitivity and the SNR ofthe image have a corresponding improvement.

FIG. 5 is a schematic diagram of imaging light in accordance with oneembodiment of the present disclosure. Wherein, one micro-lens 112corresponds to one filter cell 113 and four photosensitive pixels 111.FIG. 6 is a schematic diagram of imaging light of the related art.Wherein, one micro-lens 112 corresponds to one filter cell 113 and onephotosensitive pixel 111. As shown in FIG. 1 and FIG. 5, if the pixelinformation of the four photosensitive pixels 111 is combined to beoutput, the signal will becomes 4 times than that of the pixel structureshown in FIG. 6, and noise will be only 2 times than that of the pixelstructure shown in FIG. 6, thus both the sensitivity and the SNR of theimage have a corresponding improvement.

As can be seen, the pixel information output method of the image sensor100 of the embodiment of the present disclosure, based on the structurein which one micro-lens 31 corresponds to one filter cell 21 and aplurality of photosensitive pixels 110, makes the pixel information ofthe plurality of photosensitive pixels 110 of the same photosensitiveunit 11 be combined to be output, when the first output mode isselected. Compared with the output of a single photosensitive pixel 111of the related art, this can improve the imaging sensitivity and the SNRto improve the image quality.

In order to satisfy a condition of the phase detection to realize phasefocusing, when the second output mode is selected, the pixel informationof the plurality of photosensitive pixels 110 of the same photosensitiveunit 11 is controlled to be individually output. And then, the imaginglight can be distinguished to obtain the phase difference information ofimaging according to the pixel information of the plurality ofphotosensitive pixels 110 of the photosensitive unit 11, and the phasefocusing can be adjusted according to the phase difference information.

According to relevant knowledge, for the pixel structure shown in FIG.6, which one micro-lens 112 corresponds to one filter cell 113 and onephotosensitive pixel 111, the imaging light passes through themicro-lens and is then converged on the photosensitive pixel to beimaged, in the case of focus as shown in FIG. 7(1). In the case ofdefocus, as shown in FIG. 7(2), the imaging light diverges, and eachmicro-lens receives the divergence light from serveal directions to beimaged by the corresponding photosensitive pixels below. Because thesame photosensitive pixel cannot distinguish direction of the receivedlight, the condition of the phase detection can not be met. In therelated art, in general, in order to achieve the PDAF (Phase DetectionAuto Focus), physical design of pairs of adjacent photosensitive pixels(a.k.a. masked pixels, the masked pixel has a more complicated structurethan an ordinary photosensitive pixel. In general, it needs to changethe structure of the ordinary photosensitive pixel or increase a lightmask on the structure of the ordinary photosensitive pixel alone, sothat the light of particular direction, which is in the light fromseveral directions toward the masked pixel, can not reach thephotosensitive portion of the masked pixel, and the light except of theparticular direction can reach the photosensitive portion of the maskedpixel. In other words, the masked pixels are usually arranged in pairs,proximity, and symmetry. The pairs of masked pixels are used to splitthe light from several directions) in the image sensor is used to splitthe imaging light, toward the pairs of masked pixels and from severaldirections, into left and right two parts. The distance, which thecamera lens needs to be moved, can be calculated by means of comparingthe phase differences (that is, by collecting outputs of the pairs ofthe masked pixels) after imaging using the light of the left and rightparts.

In the embodiment of the present disclosure, based on each micro-lens 31corresponds to a filter cell 21 and a photosensitive unit 11, and eachphotosensitive unit 11 includes a plurality of photosensitive pixels110, that is, each micro-lens 31 corresponds to a plurality ofphotosensitive pixels 110. Therefore, the light received by eachmicro-lens 31 is used to be imaged by the plurality of photosensitivepixels 110. The pixel information of the plurality of photosensitivepixels 110 of the same photosensitive unit 11 is controlled to beindividually output, so that light signals from several directions canbe captured. It can be seen that the above structure plays a role insplitting the imaging light. And then, the imaging light can beidentified according to the pixel information output of the plurality ofphotosensitive pixels 110 of each photosensitive unit 11. The phasedifference information of the image can be obtained by comparing thelight signals from different directions. Furthermore, the distance of ashooting object is captured according to the phase differenceinformation, and a data basis is provided for the phase focusing and thedepth information test. Obviously, in the embodiment of the presentdisclosure, the phase focusing detection can be achieved only bycooperative design among the micro-lens array 30, the filter cell array20, and the photosensitive unit array 10. Thus, there is no need tochange the structure of the ordinary photosensitive pixel or increase alight mask on the structure of the ordinary photosensitive pixel alone,and the approach to realize the phase focusing detection is easier.

For example, as shown in FIG. 5, when the pixel information of the fourphotosensitive pixels 111 of each photosensitive unit 11 is respectivelyread, the light signals from different directions, i.e. up, down, left,right light signals, can be captured according to the pixel informationoutputs of the four photosensitive pixels 111. The phase differenceinformation of the whole image can be obtained by comparing the lightsignals from different directions. And then, the phase differenceinformation can be converted into the focusing distance information, andthe phase focusing can be achieved by means of adjusting the position ofthe camera lens in accordance with the focusing distance information.

In summary, the pixel information output method of the image sensor 100of the embodiment of the present disclosure, based on an arrangementthat each micro-lens 31 corresponds to the plurality of photosensitivepixels 110, two work states can be achieved. The first work state isthat the pixel information of the plurality of photosensitive pixels 110of each photosensitive unit 11 is combined to be output to improve theimage quality. Another work state is that the pixel information of theplurality of photosensitive pixels 110 of each photosensitive unit 11 isindividually output, and the phase difference information can beobtained by comparing the information among the photosensitive pixels110, thereby providing a data basis for the phase focusing and the depthinformation test.

A phase focusing method of an embodiment of the present disclosure, ofone aspect, is explained below.

FIG. 8 is a flow chart of a phase focusing method, according to anembodiment of the present disclosure. As shown in FIG. 8, the phasefocusing method includes the following steps to:

S10, provide an image sensor 100.

The image sensor 100 includes a photosensitive unit array 10, a filtercell array 20, and a micro-lens array 30. The filter cell array 20 islocated between the photosensitive unit array 10 and the micro-lensarray 30. The photosensitive unit array 10 includes a plurality ofphotosensitive units 11. The filter cell array 20 includes a pluralityof filter cells 21. The micro-lens array 30 includes a plurality ofmicro-lenses 31. Each micro-lens 31 covers a corresponding filter cell21 and a corresponding photosensitive unit 11. Each photosensitive unit11 includes a plurality of photosensitive pixels 110, which means eachmicro-lens 31 corresponds to a plurality of photosensitive pixels 110.

S20, control exposure of the photosensitive unit array 10, and readoutputs of the photosensitive unit array 10. Wherein, pixel informationof the plurality of photosensitive pixels 110 of the same photosensitiveunit 11 is individually output.

S30, distinguish imaging light to obtain phase difference information ofimaging according to the pixel information of the plurality ofphotosensitive pixels 110 of the photosensitive unit 11, and adjust thephase focusing according to the phase difference information.

The phase focusing method of the present disclosure, based on thestructure of the image sensor 100 in which each micro-lens 31corresponds to one filter cell 21 and a plurality of photosensitivepixels 110, makes the pixel information of the plurality ofphotosensitive pixels 110 of the same photosensitive unit 11individually output. In a defocus state, each photosensitive unit 11 canobtain light signals from different directions to provide a conditionfor the phase focusing, and then the phase difference information can beobtained to realize the phase focusing.

An imaging device 1000 of an embodiment of the present disclosure, ofanother aspect, is explained below.

FIG. 9 is a block diagram of an imaging device 1000, according to anembodiment of the present disclosure. As shown in FIG. 9, the imagingdevice 1000 includes the above-mentioned image sensor 100 and a controlmodule 200.

The control module 200 determines an output mode according to a modeselection instruction, controls the exposure of the photosensitive unitarray 10, and outputs of the photosensitive unit array 10 are read.Wherein, when the first output mode is selected, the control module 200controls the pixel information of the plurality of photosensitive pixels110 of a same photosensitive unit 11 to be combined to be output.

The imaging device 1000 of the present disclosure, based on thestructure of the image sensor 100 in which each micro-lens 31corresponds to one filter cell 21 and a plurality of photosensitivepixels 110, the control module 200 makes the pixel information of thephotosensitive pixels 110 of the same photosensitive unit 11 be combinedto be output, when the first output mode is selected. Compared with theoutput of the single photosensitive pixel 111 of the related art, thiscan improve the imaging sensitivity and the SNR to improve the imagequality.

In the embodiment of the present disclosure, when the second output modeis selected, the control module 200 controls the pixel information ofthe photosensitive pixels 110 of the same photosensitive unit 11 to beindividually output. The control module 200 distinguishes the imaginglight to obtain phase difference information of imaging according to thepixel information of the photosensitive pixels 110 of the photosensitiveunit 11, and adjusts the phase focusing according to the phasedifference information.

A terminal 2000 of an embodiment of the present disclosure, of anotheraspect, is provided. As shown in FIG. 10, the terminal 2000 includes theimaging device 1000 of the above-mentioned embodiment. The terminal 2000can take a picture, and have an improving image quality and a phasedetection function.

An imaging device 1000 of an embodiment of the present disclosure, ofanother aspect, is described below referring to the figures. The imagingdevice 1000 includes an image sensor 100 and a control module 200.

The control module 200 controls the exposure of the photosensitive unitarray 10 of the image sensor 100, and the outputs of the photosensitiveunit array 10 are read. Wherein, the control module 200 controls thepixel information of the photosensitive pixels 110 of the samephotosensitive unit 11 to be individually output, distinguishes theimaging light to obtain phase difference information of imagingaccording to the pixel information of the plurality of photosensitivepixels 110 of the photosensitive unit 11, and adjusts the phase focusingaccording to the phase difference information.

The imaging device 1000 of the present disclosure, based on thestructure of the image sensor 100 in which each micro-lens 31corresponds to one filter cell 21 and a plurality of photosensitivepixels 110, the control module 200 makes the pixel information of thephotosensitive pixels 110 of the same photosensitive unit 11 beindividually output. In a defocus state, each photosensitive unit 11 canobtain light signals from different directions to provide a conditionfor the phase focusing, and then the phase difference information can beobtained to provide a basis for realizing the phase focusing.

A terminal 2000 of an embodiment of the present disclosure, of anotheraspect, is described below referring to the figures. The terminal 2000includes the imaging device 1000 of the above-mentioned embodiment. Theterminal 2000 has a phase focusing function.

In detail, the terminal 2000 can include, but is not limited to, cellphones.

The imaging device 1000 can include a front-facing camera(s), obtainfocusing distance information according to the phase differenceinformation, and then adjust the distance of the front-facing cameraaccording to the focusing distance information to realize the phasefocusing.

Based on the image sensor 100 of the above-mentioned embodiment, whereinthe image sensor 100 includes a photosensitive unit array 10, a filtercell array 20, and a micro-lens array 30. The filter cell array 20 islocated between the photosensitive unit array 10 and the micro-lensarray 30. The photosensitive unit array 10 includes a plurality ofphotosensitive units 11. The filter cell array 20 includes a pluralityof filter cells 21. The micro-lens array 30 includes a plurality ofmicro-lenses 31. Each micro-lens 31 covers a corresponding filter cell21 and a corresponding photosensitive unit 11. Each photosensitive unit11 includes a plurality of photosensitive pixels 110. An imaging methodof an embodiment of the present disclosure is described below referringto the figures.

FIG. 11 is a flow chart of an imaging method, according to an embodimentof the present disclosure. As shown in FIG. 11, the imaging methodincludes the following steps to:

S1, read outputs of the photosensitive unit array 10.

S2, add the outputs of the plurality of photosensitive pixels 110 of asame photosensitive unit 11 to obtain a pixel value of thephotosensitive unit 11, thereby producing a merged image.

The imaging method of the embodiment of the present disclosure, assumingthe output of each original photosensitive unit 11 is represented as S,the noise is represented as N, the photosensitive unit 11 includes Mphotosensitive units 11, the pixel value of the photosensitive unit 11can be represented as n*m*S, and the noise of the photosensitive unit 11is represented as

$\frac{\sqrt{n*m*N^{2}}}{n*m}.$In a case that n=2, and m=2, the noise of the photosensitive unit 11 isabout n*m*N/2. Therefore, the brightness of the photosensitive unit 11in a low-luminance environment is improved, and the SNR is improved.

Referring to FIG. 12, in some embodiments, each photosensitive unit 11includes 2*2 photosensitive pixels 110. The image sensor 100 includes aregister, the step of S2 further includes:

S201, gather and store the outputs of the photosensitive pixels 110 ofrows k and k+1 into the register, wherein k=2n−1, n is a natural number,k+1 is less than or equal to the total row of the photosensitive pixels110.

S202, extract the outputs of the photosensitive pixels 110 of rows k andk+1 from the register, and add the outputs of the photosensitive pixels110 of the same photosensitive unit 11 to obtain a pixel value of thephotosensitive unit 11.

Thus, a process of reading, caching, and combining the outputs of thephotosensitive pixels 110 can be achieved using the register.

Referring to FIG. 13, in some embodiments, the step of S2 furtherincludes:

S301, convert analog signal outputs of the photosensitive pixels 110into digital signal outputs; and

S302, add the outputs of the photosensitive pixels 110 of the samephotosensitive unit 11 to obtain a pixel value of the photosensitiveunit 11.

Thus, an image processing module as a digital signal processing chip candirectly process outputs of the image sensor, and compared with somesolutions of directly processing the outputs of the image sensor with ananalog signal format through a circuit, the image information is betterreserved. For example, for an image sensor with 16M pixels, the imagingmethod of the present disclosure can both produce a megered image with4M pixels (which combines the 2*2 pixels), and produce an original imagewith 16M pixels (which is not combined).

A mobile terminal 2000 of an embodiment of the present disclosure, inanother aspect, is provided. The terminal 2000 includes a housing, aprocessor, a storage, a circuit board, and a power circuit. Wherein, thecircuit board is positioned inside a space surrounded by the housing.The processor and the storage are disposed on the circuit board. Thepower circuit is configured to supply power for each electric circuit orcomponent of the mobile terminal. The storage is configured to storeexecutable program codes. The processor executes a program correspondingto the executable program codes, by means of reading the executableprogram codes stored in the storage, for executing the above-mentionedimaging method.

A computer-readable storage medium of an embodiment of the presentdisclosure is also provided. The computer-readable storage mediumincludes instructions stored therein. When a processor of the mobileterminal executes the instructions, the mobile terminal executes theimaging method of the embodiments of the present disclosure, as shown inFIG. 11.

It should be noted that the relational terms herein, such as “first” and“second”, are used only for differentiating one entity or operation,from another entity or operation, which, however do not necessarilyrequire or imply that there should be any real relationship or sequence.Moreover, the terms “comprise”, “include” or any other variationsthereof are meant to cover non-exclusive including, so that the process,method, article or device comprising a series of elements do not onlycomprise those elements, but also comprise other elements that are notexplicitly listed or also comprise the inherent elements of the process,method, article or device. In the case that there are no morerestrictions, an element qualified by the statement “comprises a . . . ”does not exclude the presence of additional identical elements in theprocess, method, article or device that comprises the said element.

The logic and/or steps described in other manners herein or shown in theflow chart, for example, a particular sequence table of executableinstructions for realizing the logical function, may be specificallyachieved in any computer-readable storage medium to be used by theinstruction execution system, device or equipment (such as the systembased on computers, the system comprising processors or other systemscapable of obtaining the instruction from the instruction executionsystem, device and equipment and executing the instruction), or to beused in combination with the instruction execution system, device andequipment. As to the specification, “the computer-readable storagemedium” may be any device adaptive for including, storing,communicating, propagating or transferring programs to be used by or incombination with the instruction execution system, device or equipment.More specific examples of the computer-readable storage medium comprisebut are not limited to: an electronic connection (an electronic device)with one or more wires, a portable computer enclosure (a magneticdevice), a random access memory (RAM), a read only memory (ROM), anerasable programmable read-only memory (EPROM or a flash memory), anoptical fiber device, and a portable compact disk read-only memory(CDROM). In addition, the computer readable medium may even be a paperor other appropriate medium capable of printing programs thereon, thisis because, for example, the paper or other appropriate medium may beoptically scanned and then edited, decrypted or processed with otherappropriate methods when necessary to obtain the programs in an electricmanner, and then the programs may be stored in the computer memories.

It should be understood that each part of the present disclosure may berealized by the hardware, software, firmware or their combination. Inthe above embodiments, a plurality of steps or methods may be realizedby the software or firmware stored in the memory and executed by theappropriate instruction execution system. For example, if it is realizedby the hardware, likewise in another embodiment, the steps or methodsmay be realized by one or a combination of the following techniquesknown in the art: a discrete logic circuit having a logic gate circuitfor realizing a logic function of a data signal, an application-specificintegrated circuit having an appropriate combination logic gate circuit,a programmable gate array (PGA), a field programmable gate array (FPGA),etc.

Reference throughout this specification to “an embodiment,” “someembodiments,” “an example,” “a specific example,” or “some examples,”means that a particular feature, structure, material, or characteristicdescribed in connection with the embodiment or example is included in atleast one embodiment or example of the present disclosure. Thus, theschematic expressions of the above-mentioned phrases throughout thisspecification are not necessarily referring to the same embodiment orexample of the present disclosure. Furthermore, the particular features,structures, materials, or characteristics can be combined in anysuitable manner in any one or more embodiments or examples. In addition,in the case that it is not contradictory, a person of skilled in the artcan combine different embodiments or examples and the features ofdifferent embodiments or examples.

Although explanatory embodiments have been shown and described, it wouldbe appreciated by those skilled in the art that the above embodimentscannot be construed to limit the present disclosure, and changes,alternatives, and modifications can be made in the embodiments withoutdeparting from scope of the present disclosure.

What is claimed is:
 1. A method for outputting pixel information of animage sensor, the image sensor comprising a photosensitive unit array, afilter cell array, and a micro-lens array, the filter cell array locatedabove the photosensitive unit array, the micro-lens array located abovethe filter cell array, each micro-lens covering a corresponding filtercell and a corresponding photosensitive unit, each photosensitive unitcomprising four photosensitive pixels, the method comprising:determining an output mode according to a mode selection instruction,wherein the output mode comprises a first output mode and a secondoutput mode, the first output mode is configured to improve an imagingsensitivity and a signal-to-noise ratio, and the second output mode isconfigured to realize a phase focusing; and controlling exposure of thephotosensitive unit array, and reading outputs of the photosensitiveunit array; controlling pixel information of four photosensitive pixelsof a same photosensitive unit to be combined to be output when theoutput mode is the first output mode; controlling the pixel informationof the four photosensitive pixels of the same photosensitive unit to beindividually output when the output mode is the second output mode,distinguishing imaging light according to the pixel information of thefour photosensitive pixels of the photosensitive unit to obtain phasedifference information for imaging, and adjusting the phase focusingaccording to the phase difference information; gathering and storing theoutputs of the photosensitive pixels of rows k and k+1 into a register,wherein k=2n−1, n is a natural number, k+1 is less than or equal to thetotal row of the photosensitive pixels, each photosensitive unitcomprises 2*2 photosensitive pixels, the image sensor comprises theregister; and extracting the outputs of the photosensitive pixels ofrows k and k+1 from the register, and adding the outputs of thephotosensitive pixels of the same photosensitive unit to obtain a pixelvalue of the photosensitive unit.
 2. The method of claim 1, comprising:converting analog signal outputs of the photosensitive pixels intodigital signal outputs.
 3. A phase focusing method comprising: providingan image sensor, and determining an output mode according to a modeselection instruction, the image sensor comprising a photosensitive unitarray, a filter cell array, and a micro-lens array, the filter cellarray located above the photosensitive unit array, the micro-lens arraylocated above the filter cell array, each micro-lens covering acorresponding filter cell and a corresponding photosensitive unit, eachphotosensitive unit comprising four photosensitive pixels, wherein theoutput mode comprises a first output mode and a second output mode, thefirst output mode is configured to improve an imaging sensitivity and asignal-to-noise ratio, and the second output mode is configured torealize a phase focusing; controlling exposure of the photosensitiveunit array and reading outputs of the photosensitive unit array;controlling pixel information of photosensitive pixels of a samephotosensitive unit to be individually output when the output mode isthe second output mode; and distinguishing imaging light to obtain phasedifference information for imaging according to the pixel information ofthe photosensitive pixels of the photosensitive unit, and adjusting thephase focusing according to the phase difference information; gatheringand storing the outputs of the photosensitive pixels of rows k and k+1into a register, wherein k=2n−1, n is a natural number, k+1 is less thanor equal to the total row of the photosensitive pixels, eachphotosensitive unit comprises 2*2 photosensitive pixels, the imagesensor comprises the register; and extracting the outputs of thephotosensitive pixels of rows k and k+1 from the register, and addingthe outputs of the photosensitive pixels of the same photosensitive unitto obtain a pixel value of the photosensitive unit.
 4. An imagingdevice, comprising: an image sensor comprising: a photosensitive unitarray; a filter cell array, located above the photosensitive unit array;and a micro-lens array, located above the filter cell array, eachmicro-lens covering a corresponding filter cell and a correspondingphotosensitive unit, each photosensitive unit comprising fourphotosensitive pixels, and a control module, configured to determine anoutput mode according to a mode selection instruction, and controlexposure of the photosensitive unit array and read outputs of thephotosensitive unit array, wherein the output mode comprises a firstoutput mode and a second output mode, the first output mode isconfigured to improve an imaging sensitivity and a signal-to-noiseratio, and the second output mode is configured to realize a phasefocusing, the control module is further configured to control pixelinformation of four photosensitive pixels of a same photosensitive unitto be combined to be output when the output mode is the first outputmode; the control module is further configured to control the pixelinformation of the four photosensitive pixels of the same photosensitiveunit to be individually output when the output mode is the second outputmode, distinguish imaging light according to the pixel information ofthe four photosensitive pixels of the photosensitive unit to obtainphase difference information for imaging, and adjust the phase focusingaccording to the phase difference information, wherein eachphotosensitive unit comprises 2*2 photosensitive pixels, the imagesensor comprises a register, and the control module is configured to:gather and store the outputs of the photosensitive pixels of rows k andk+1 into the register, wherein k=2n−1, n is a natural number, k+1 isless than or equal to the total row of the photosensitive pixels; andextract the outputs of the photosensitive pixels of rows k and k+1 fromthe register, and add the outputs of the photosensitive pixels of thesame photosensitive unit to obtain a pixel value of the photosensitiveunit.
 5. The imaging device of claim 4, wherein each photosensitive unitcomprises 2*2 photosensitive pixels.
 6. The imaging device of claim 4,wherein the filter cell array comprises a Bayer array.
 7. The imagingdevice of claim 4, wherein the control module is configured to: convertanalog signal outputs of the photosensitive pixels into digital signaloutputs.